Methods: Laboratory and billing records were abstracted for adult patients admitted to the Detroit Medical Center and Henry Ford Health System (Detroit, MI) from 2006 to 2012. All inpatients receiving linezolid were identified and randomly matched 1:3 by health system and year to patients receiving another antibiotic (vancomycin, clindamycin, daptomycin, trim-sulfa, ceftaroline, doxycycline). Clinical and demographic variables were abstracted from medical records. Readmissions were captured at any included hospital system. A propensity score was calculated to predict treatment assignment using stepwise model selection with a threshold of 0.2. Clinical outcomes were compared between groups using logistic regression with inverse probability weighting.
Results: 164 hospitalized patients with MRSA-ABSSSI were treated with linezolid over the six year period and were matched to 502 comparison patients. The multivariate propensity model of differences between treatment groups included hospital transfer, severe sepsis, history of previous hospitalization, current ICU admission, renal failure, bacteremia and stage 4 ulcer. The all-cause readmission rate was 25% (41/164) in the linezolid group and 20% (100/505) in the comparison group. Following propensity weighting, all-cause 30-day readmission was not statistically different between groups (OR: 1.2 (95% C.I. 0.8, 2.0); p=0.38). This estimate was significantly modified between those with diabetes (OR: 0.6 (95% C.I. 0.3, 1.3); p=0.20) versus those without (OR: 1.8 (0.98, 3.4); 0.06) (p=0.03 for interaction).
Conclusion: Our analysis did not identify a difference between inpatients with MRSA-ABSSSI treated with linezolid versus other antibiotics with regards to 30-day all-cause readmission. However, we did find a significant interaction by diabetes status. The potential for an increased treatment benefit with linezolid among patients with diabetes warrants further investigation.
E. T. Martin,
M. Compton, None
J. Pogue, CUBIST: Consultant and Speaker's Bureau , Consulting fee , Research grant and Speaker honorarium
Actavis: Speaker's Bureau , Speaker honorarium
theravance: Consultant and Speaker's Bureau , Consulting fee and Speaker honorarium
P. Lephart, None
M. J. Rybak, None
K. Kaye, Detroit Medical Center and Wayne State University: Consultant and Grant Investigator , Consulting fee and Grant recipient
S. L. Davis, None
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